What are the influcences of shaking diameter and frequency on the cultivation?This is one of the most commonly ask question of users. The Department of Biochemical Engineering at the RWTH Aachen, Germany had measured the influence. The results are presented in the following figure.
The figure illustrates the influence of the shaking diameter and frequency on the oxygen supply (OTR=oxygen transfer rate) of the culture. The oxygen transfer rate discribes the oxygen mass transport from the gas phase of the shake flask into the liquid phase. The oxygen transfer rate (OTR) is nearly equivalent to the oxygen uptake rate (OUR) of the culture (dependent on the medium composition). The measuring was carried out with the RAMOS-Technology.
 figure: oxygen transfer rate [mol/L/h] dependent on the shaking frequency and diameter, sulfit-system was used
The measured curves visualise very clearly that the oxygen transfer rate rises with increasing shaking frequency and shaking diameter. Especially the differences in the oxygen transfer rate levels between 25mm and 50mm shaking diameter are obvious.
Conclusion:
Cultivating a great oxygen demanding microorganismen strain (e.g. E. coli) a high shaking frequency (> 300 RPM) and shaking diameter (>50 mm) should be adjusted at the shaker.
This example illustrates only a small section of the consulting service Kühner AG provides to their customers. Mostly topics like screening conditions and scale up questions are discussed with our customers.
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Further examples of our service:
+ scale up + plug choice + fermentation in microtiter plates + tilting angle of test tubes + out of phase phenomenon + baffles + ... |
